Disc or roll screens are used in the materials handling industry for screening flows of materials to remove certain items of desired dimensions. Disc screens are particularly suitable for classifying what is normally considered debris or residual materials. This debris may consist of soil, aggregate, asphalt, concrete, wood, biomass, ferrous and nonferrous metal, plastic, ceramic, paper, cardboard, paper products or other materials recognized as debris throughout consumer, commercial and industrial markets. The function of the disc screen is to separate the materials fed into it by size or type of material. The size classification may be adjusted to meet virtually any application.
Material separating screens, and more specifically the discs in those screens, have been modified to improve the efficiency of separating out material from flows of debris introduced to the screen. Examples of those modifications are found in U.S. Pat. No. 5,960,964 to Austin et al., U.S. Pat. No. 6,149,018 to Austin et al., and U.S. Pat. No. 6,371,305 to Austin et al., which are incorporated by reference herein.
Discs must be routinely replaced on material separating screens when the discs wear down due to the normal operation of the screen. Replacing each individual disc involves removing the worn discs by disassembling each disc into its two halves. New discs are then installed on the drive shafts, with each new half disc fastened to that half disc's corresponding other half.
A typical screen will employ around 600 individual discs. Removal and replacement of all these discs is time-consuming. The process also requires at least two workers to perform the removal and replacement because a first disc half is held in place on the drive shaft by one worker while a second worker attaches or removes the second disc half that attaches to the first disc half.
What is needed is a material separating screen that requires less time to perform replacement of discs and reduces the man-power required to perform the replacement.